diff options
Diffstat (limited to 'arch/x86/kernel/i387.c')
| -rw-r--r-- | arch/x86/kernel/i387.c | 168 |
1 files changed, 149 insertions, 19 deletions
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index eb9ddd8efb82..1f20608d4ca8 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -21,9 +21,12 @@ # include <asm/sigcontext32.h> # include <asm/user32.h> #else -# define save_i387_ia32 save_i387 -# define restore_i387_ia32 restore_i387 +# define save_i387_xstate_ia32 save_i387_xstate +# define restore_i387_xstate_ia32 restore_i387_xstate # define _fpstate_ia32 _fpstate +# define _xstate_ia32 _xstate +# define sig_xstate_ia32_size sig_xstate_size +# define fx_sw_reserved_ia32 fx_sw_reserved # define user_i387_ia32_struct user_i387_struct # define user32_fxsr_struct user_fxsr_struct #endif @@ -36,6 +39,7 @@ static unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu; unsigned int xstate_size; +unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32); static struct i387_fxsave_struct fx_scratch __cpuinitdata; void __cpuinit mxcsr_feature_mask_init(void) @@ -61,6 +65,11 @@ void __init init_thread_xstate(void) return; } + if (cpu_has_xsave) { + xsave_cntxt_init(); + return; + } + if (cpu_has_fxsr) xstate_size = sizeof(struct i387_fxsave_struct); #ifdef CONFIG_X86_32 @@ -83,9 +92,19 @@ void __cpuinit fpu_init(void) write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */ + /* + * Boot processor to setup the FP and extended state context info. + */ + if (!smp_processor_id()) + init_thread_xstate(); + xsave_init(); + mxcsr_feature_mask_init(); /* clean state in init */ - current_thread_info()->status = 0; + if (cpu_has_xsave) + current_thread_info()->status = TS_XSAVE; + else + current_thread_info()->status = 0; clear_used_math(); } #endif /* CONFIG_X86_64 */ @@ -195,6 +214,13 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset, */ target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask; + /* + * update the header bits in the xsave header, indicating the + * presence of FP and SSE state. + */ + if (cpu_has_xsave) + target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE; + return ret; } @@ -395,6 +421,12 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset, if (!ret) convert_to_fxsr(target, &env); + /* + * update the header bit in the xsave header, indicating the + * presence of FP. + */ + if (cpu_has_xsave) + target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FP; return ret; } @@ -407,7 +439,6 @@ static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf) struct task_struct *tsk = current; struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave; - unlazy_fpu(tsk); fp->status = fp->swd; if (__copy_to_user(buf, fp, sizeof(struct i387_fsave_struct))) return -1; @@ -421,8 +452,6 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf) struct user_i387_ia32_struct env; int err = 0; - unlazy_fpu(tsk); - convert_from_fxsr(&env, tsk); if (__copy_to_user(buf, &env, sizeof(env))) return -1; @@ -432,16 +461,54 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf) if (err) return -1; - if (__copy_to_user(&buf->_fxsr_env[0], fx, - sizeof(struct i387_fxsave_struct))) + if (__copy_to_user(&buf->_fxsr_env[0], fx, xstate_size)) + return -1; + return 1; +} + +static int save_i387_xsave(void __user *buf) +{ + struct task_struct *tsk = current; + struct _fpstate_ia32 __user *fx = buf; + int err = 0; + + /* + * For legacy compatible, we always set FP/SSE bits in the bit + * vector while saving the state to the user context. + * This will enable us capturing any changes(during sigreturn) to + * the FP/SSE bits by the legacy applications which don't touch + * xstate_bv in the xsave header. + * + * xsave aware applications can change the xstate_bv in the xsave + * header as well as change any contents in the memory layout. + * xrestore as part of sigreturn will capture all the changes. + */ + tsk->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE; + + if (save_i387_fxsave(fx) < 0) + return -1; + + err = __copy_to_user(&fx->sw_reserved, &fx_sw_reserved_ia32, + sizeof(struct _fpx_sw_bytes)); + err |= __put_user(FP_XSTATE_MAGIC2, + (__u32 __user *) (buf + sig_xstate_ia32_size + - FP_XSTATE_MAGIC2_SIZE)); + if (err) return -1; + return 1; } -int save_i387_ia32(struct _fpstate_ia32 __user *buf) +int save_i387_xstate_ia32(void __user *buf) { + struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf; + struct task_struct *tsk = current; + if (!used_math()) return 0; + + if (!access_ok(VERIFY_WRITE, buf, sig_xstate_ia32_size)) + return -EACCES; /* * This will cause a "finit" to be triggered by the next * attempted FPU operation by the 'current' process. @@ -451,13 +518,17 @@ int save_i387_ia32(struct _fpstate_ia32 __user *buf) if (!HAVE_HWFP) { return fpregs_soft_get(current, NULL, 0, sizeof(struct user_i387_ia32_struct), - NULL, buf) ? -1 : 1; + NULL, fp) ? -1 : 1; } + unlazy_fpu(tsk); + + if (cpu_has_xsave) + return save_i387_xsave(fp); if (cpu_has_fxsr) - return save_i387_fxsave(buf); + return save_i387_fxsave(fp); else - return save_i387_fsave(buf); + return save_i387_fsave(fp); } static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf) @@ -468,14 +539,15 @@ static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf) sizeof(struct i387_fsave_struct)); } -static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf) +static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf, + unsigned int size) { struct task_struct *tsk = current; struct user_i387_ia32_struct env; int err; err = __copy_from_user(&tsk->thread.xstate->fxsave, &buf->_fxsr_env[0], - sizeof(struct i387_fxsave_struct)); + size); /* mxcsr reserved bits must be masked to zero for security reasons */ tsk->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask; if (err || __copy_from_user(&env, buf, sizeof(env))) @@ -485,14 +557,69 @@ static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf) return 0; } -int restore_i387_ia32(struct _fpstate_ia32 __user *buf) +static int restore_i387_xsave(void __user *buf) +{ + struct _fpx_sw_bytes fx_sw_user; + struct _fpstate_ia32 __user *fx_user = + ((struct _fpstate_ia32 __user *) buf); + struct i387_fxsave_struct __user *fx = + (struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0]; + struct xsave_hdr_struct *xsave_hdr = + ¤t->thread.xstate->xsave.xsave_hdr; + u64 mask; + int err; + + if (check_for_xstate(fx, buf, &fx_sw_user)) + goto fx_only; + + mask = fx_sw_user.xstate_bv; + + err = restore_i387_fxsave(buf, fx_sw_user.xstate_size); + + xsave_hdr->xstate_bv &= pcntxt_mask; + /* + * These bits must be zero. + */ + xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0; + + /* + * Init the state that is not present in the memory layout + * and enabled by the OS. + */ + mask = ~(pcntxt_mask & ~mask); + xsave_hdr->xstate_bv &= mask; + + return err; +fx_only: + /* + * Couldn't find the extended state information in the memory + * layout. Restore the FP/SSE and init the other extended state + * enabled by the OS. + */ + xsave_hdr->xstate_bv = XSTATE_FPSSE; + return restore_i387_fxsave(buf, sizeof(struct i387_fxsave_struct)); +} + +int restore_i387_xstate_ia32(void __user *buf) { int err; struct task_struct *tsk = current; + struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf; if (HAVE_HWFP) clear_fpu(tsk); + if (!buf) { + if (used_math()) { + clear_fpu(tsk); + clear_used_math(); + } + + return 0; + } else + if (!access_ok(VERIFY_READ, buf, sig_xstate_ia32_size)) + return -EACCES; + if (!used_math()) { err = init_fpu(tsk); if (err) @@ -500,14 +627,17 @@ int restore_i387_ia32(struct _fpstate_ia32 __user *buf) } if (HAVE_HWFP) { - if (cpu_has_fxsr) - err = restore_i387_fxsave(buf); + if (cpu_has_xsave) + err = restore_i387_xsave(buf); + else if (cpu_has_fxsr) + err = restore_i387_fxsave(fp, sizeof(struct + i387_fxsave_struct)); else - err = restore_i387_fsave(buf); + err = restore_i387_fsave(fp); } else { err = fpregs_soft_set(current, NULL, 0, sizeof(struct user_i387_ia32_struct), - NULL, buf) != 0; + NULL, fp) != 0; } set_used_math(); |